1. Field of the Invention
The present invention relates generally to axial tumbler locks, and, more particularly, relates to an improved type of construction for tubular wafer tumbler locks which can be automatically manufactured and assembled along with a cast combinated key at very low cost without machining operations. The preliminary form of such a lock was disclosed in Disclosure Document No. 165575, filed in the U.S. Patent and Trademark Office on March 9, 1987.
2. Description of the Prior Art
U.S. Pat. No. 3,237,436 discloses a tubular lock structure of the type with which the present invention is concerned. The lock of that patent has been in commercial use. While that lock did provide the desirable aspects of manufacture and assembly without machining operations as well as the capability of casting a corresponding combinated key, there were several areas of deficiency with respect to the construction and manner of assembly of the components which limited the versatility of the lock. Also, the particular component structures did not readily lend themselves to fully automated assembly to minimize manufacturing costs for achieving optimum advantages of this type of tubular lock construction.